Semi-quantitative Analysis of Low-molecular-weight Cyclic Siloxane in Silicone Rubber via Pyrolysis GC/MS
Product: JMS-Q1500GC GC/MS System
Introduction
Silicone rubber is made from low-molecular-weight (LMW) cyclic siloxane. Most LMW cyclic siloxane is used up during the polymerization process, and the residual cyclic siloxane is removed by subsequent heating and depressurization steps. Generally, the residual level of cyclic siloxane is <3% in silicone rubber, but in the field of electronic equipment manufacturing, residual cyclic siloxane levels must be < 1% in order to avoid contact failure of relays, connectors, etc. due to gases evolved by LMW cyclic siloxane. In this application note, we show semi-quantitative analysis results of LMW cyclic siloxane in silicone rubber that was analyzed using the EGA/PY-3030D pyrolyzer (Py) (Frontier Laboratories, Ltd.) and the gas chromatography–quadrupole mass-spectrometer (GC/QMS) instrument JMS-Q1500GC (JEOL).
Experiment
A silicone rubber septum for a crimp vial was used as a measurement sample, which was weighed at 1 mg. Decamethylcyclopentasiloxane (Si D5) 1000 ng was used as a standard for quantification. Si D5 1000 ng was taken from 10 μL of Si D5 100ng/ μL methanol solution using a micro-syringe. Table 1 shows the measurement conditions.